This invention relates to improvements in shelf supports of the type primarily intended for supporting shelves between opposed uprights, for instance cabinet walls or walls at the ends of bookcases. Prior art shelf supports of the foregoing general type are shown and described in U.S. Pat. Nos. 3,471,111 and 3,471,112. Shelf supports of the type with which the present invention is concerned are particularly suitable for shipping shelves in cabinets with the shelving mounted in place. Nevertheless, the user of the cabinet can conveniently remove and remount the supports and the shelves in different positions so as to vary the shelf spacing.